Glad to know I'm not alone in recognizing the lyric as "And days of" rather than "for the sake of." Based on the limited evidence so far, it sure looks like a transatlantic issue, sung one way in the US and the other in the UK.

I'm not sure, and not willing to do the research, but my best guess would be that "days of" is the way that the vocalist for Guy Lombardo and his Royal Canadians did it, on live TV every New Year's Eve through the late 50s-early 60s. They probably made a widely-distributed recording as well.